1. Field
The following description relates generally to wireless communications, and more particularly to signaling primary scrambling code (PSC) information and/or dedicated frequency lists for closed subscriber group (CSG) cells.
2. Background
Wireless communication systems are widely deployed to provide various types of communication content such as, for example, voice, data, and so on. Typical wireless communication systems may be multiple-access systems capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power, . . . ). Examples of such multiple-access systems may include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, and the like. Additionally, the systems can conform to specifications such as third generation partnership project (3GPP), 3GPP long term evolution (LTE), ultra mobile broadband (UMB), and/or multi-carrier wireless specifications such as evolution data optimized (EV-DO), one or more revisions thereof, etc.
Generally, wireless multiple-access communication systems may simultaneously support communication for multiple mobile devices. Each mobile device may communicate with one or more access points (e.g., base stations) via transmissions on forward and reverse links. The forward link (or downlink) refers to the communication link from access points to mobile devices, and the reverse link (or uplink) refers to the communication link from mobile devices to access points. Further, communications between mobile devices and access points may be established via single-input single-output (SISO) systems, multiple-input single-output (MISO) systems, multiple-input multiple-output (MIMO) systems, and so forth. In addition, mobile devices can communicate with other mobile devices (and/or access points with other access points) in peer-to-peer wireless network configurations.
MIMO systems commonly employ multiple (NT) transmit antennas and multiple (NR) receive antennas for data transmission. The antennas can relate to both base stations and mobile devices, in one example, allowing bi-directional communication between the devices on the wireless network. As mobile devices move throughout wireless network service areas, cells utilized for communication, which are provided by one or more access points (e.g., macro cells, femto cells, pico cells, etc.), can be selected/reselected by the mobile device. Information regarding selection/reselection or other access parameters can be sent to mobile devices in one or more system information blocks (SIB), which can be periodically transmitted according to a preconfigured scheduling and/or priority of the SIB. In addition, access points can use a primary scrambling code (PSC) (e.g., over a pilot or other channels) to identify and/or descramble communications from the access point (e.g., SIBs or otherwise).
Some access points (also called CSG cells) can be a part of closed subscriber group (CSG) accessible only by certain mobile devices. Mobile devices can be provisioned with and/or can maintain lists of such CSG cells that indicate whether the mobile device is allowed or disallowed access to the access points (e.g., white list or blacklist). In this regard, the mobile devices can conserve power during cell selection/reselection by consulting a white list and/or blacklist, to determine whether a CSG cell is allowed, before attempting access to a respective CSG cell. Mobile device can also be provided with and/or can maintain lists/ranges that identify CSG cells according to utilized PSCs (e.g., CSG PSC split information). In this regard, the mobile devices can further conserve power during cell selection/reselection by avoiding these CSG cells altogether without reading any broadcast information (such as SIBs) if the mobile devices do not desire or are not allowed access on any CSG cell in the group. Also, the PSC lists/ranges can be used to optimize search for CSG cells and reselect to them with appropriate parameters. In addition, CSG cells operating over similar frequencies can be deployed and assigned a range of PSCs.